Foldable scaffold for household uses



June 10, 1952 G. G. THOMAS FOLDABLE SCAFFOLD FOR HOUSEHOLD USE FiledFeb. 1, 1950 INVENTOR. e oye 6. 7/20/2645 Patented June 10, 1952FOLDABLE SCAFFOLD FOR HOUSEHOLD USES George G. Thomas, Chicago, Ill.Application February 1, 1950, Serial No. 141,664

1 Claim.

The present invention relates to foldable scaffolds for household use,and is particularly concerned with the provision of an improved lightand simple scaffold which can be used in the home when walls or ceilingsare to be cleaned, papered, painted, calcimined or the like.

One of the objects of the invention is the provision of an improvedscaffold of the class described, which may be folded into a minimumamount of space and which may have all of its parts secured together inthe folded position so that it may be readily stored in a closet orstoreroom when not in use.

Another object of the invention is the provision of an improved scaffoldwhich is sturdy, Which may be rolled from place to place but which isalso adapted to be fixedly secured against rolling, and which may bequickly adjusted as to height to suit the convenience of the user.

Another object is the provision of an improved scafiold which is adaptedto fold laterally but which is safely secured against folding by theassembly of its parts when it is being used, and which is adapted tosupport a maximum weight with the use of a minimum amount of metal.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacteristics of reference indicate similar parts throughout theseveral views.

Referring to the single sheet of drawings accompanying thespecification:

Fig. 1 is a view in perspective of the scaffold as it appears when it isready for use;

Fig. 2 is a fragmentary sectional view taken on the plane of the line2-2 of Figure 1, looking in the direction of the arrows;

Fig. 3 is a fragmentary sectional view taken I on the horizontal planeof the line 3-3, looking in the direction of the arrows, showing thedetails of construction at one corner;

Fig. 4 is a side elevational view of the scaffold when folded;

Fig. 5 is a top plan view of the folded scaffold; and

Fig. 6 is a fragmentary sectional view showing the structure of the capat the upper end-of each leg.

The present scafiold is indicated in its entirety by the numeral [0, inFigure 1, and it preferably includes a platform II, which is carried byidentical end frames l2, the end frames in turn carrying the side framesl3. and being in turn supported by four identical legs l4.

Each leg l4 may consist of a steel tube which is provided at its lowerend with a caster I5, the caster preferably being of the type havingsolid rubber tired wheels 16, and provided with a brake which iscontrolled by the lever IT.

The casters [5 have their upper shank (not shown) fixedly secured ineach tubular leg, but the casters l5 rotate upon the legs and permit thescaffold tobe moved from place to place with a minimum amount of effort.

Any two casters can be secured with its wheel blocked against rotationby means of a brake I! to hold the scaffold, but I prefer to providethree of the casters with brakes for the reason that it may not beconvenient to reach the specific two casters if only two are providedwith. brakes.

By omitting the brake upon the fourth caster l5a, it is easier to knowwhich caster must be given attention when the brake is to be released.

The tubes of the legs [4 are provided with a plurality of diametricallyextending through apertures I 8, regularly spaced from each other from apoint near the bottom of each leg to a point which is spaced from thetop by a distance substantially equal to the height of the scaffoldframes.

The apertures I8 are used for a cotter pin or for an eye bolt l9, whichpasses through both apertures and supports the end frames I3 at thedesired level. The eye bolts I 9 are preferably mounted upon chains 20which are secured to an adjacent frame member, as, for example, at thepoint 2|, by means of a suitable eye bolt. Thus the eye bolts l9 cannotbe lost when withdrawn, and being secured to the longitudinallyextending frame members of the side frames I 3, the eye bolts I 9 arealso in proper position to be inserted in a suitable aperture l8,immediately below the frames at any desired level.

By means of the apertures l8 and the eye bolt IS, the height of thescaffold can be varied at will.

The end frames l2 are identical in shape and construction and eachincludes a pair of parallel transverse frame members 22, 23, and a pairof vertical frame members 24, 25. The transverse frame members 22 and 23may be substantially as large in diameter as the tubular legs H, but thevertical frame members 24 and 25 are of such a size that they can beslidably mounted on the legs l4, with only sufiicient clearance for freesliding movement.

The lateral frame members 22 and 23 are welded to the outside of thevertical frame members 24 and 25... adjacent the ends of the verticalframe members 24 and 25, so as to form a rectangle. Before welding bothframe members 22 and 23 to the vertical frame corner members 24 and 25,the corner frame members 26, 2'! must be located upon the tubes 26.

These corner frame members 23 and 21 form part of the side frames 13,and are preferably of substantially the same length as the distancebetween the end frame members 22 and 23. The lower edge of each cornerframe member 21 rests upon the side of the lower end frame member 22,which in turn is supported by the eye bolt [9 acting through the framemember '23.

The diametrical size of the frame members 26 and 21 is such that theinterior bore of these tubes has a rotating fit on the frame members 24or 25, for the purpose of permitting the folding of the scaffold.

The corner frame members 26 and 21 are joined by the longitudinallyextending frame members 23 and 29, to which they are welded. Thelongitudinal frame members 28 and 29 are welded to the corner framemembers 26, 27, adjacent their ends, thus forming a rectangular frame I3for each side. Looking at the assembled framework from the top it formsa parallelogram which is collapsible to the position shown'at the leftof Figure 5.

The platform ll may comprise wide and thick plank of rectangular shape.The width of the plank IE is preferably slightly greater than the lengthof the frame member-s 24. The length of the plank H is slightly greaterthan the distance between the similar top of "the scaffold when to .berectangular in plan.

Thus the plank l i may lie upon the top frame members 23 of the two endframes 12, and it is preferably secured there by means of a plurality ofresilient sheet metal clips 30, Figure 2. These clips 'may also be seenat the right end in Figure "1 on'the'lower side of the plank il,engaging the horizontal frame member 23, and a similar pair of clips islocated at the other end for engaging the adjacent frame member 23.

Each clip '30 comprises a resilient sheet metal member which may be madeof steel having a flat base 3! and a pair of resilient clamping fingers32, '33. At the base 3|, each finger is bentbackward to extend towardeach other and to.locate'the finger in proximity to the pipe 23.

'Each finger is then formed with an inner partially .cylindrical surface34, complementary to the pipe 23, and each finger is formed with anoutwardly turned end portion 35 to provide the clip 30 with a bellmouth. The base 3! of the clip *may have suitable apertures forreceiving the wood screws 36, by means of which the clip is securedtothe bottom of the plank l l.

Such a clip is provided adjacent each of the four corners of the bottomof the plank, and the clipsareprefera bly equally spaced from each otherand symmetrically located with regard to theplane of the plank.Longitudinally, the clips are far enough apart so that when one pairengages the left frame member 23, the other pair is in position toengage the right frame member 23.

'Thustheclips 30"secure the plank to the frame of the scaffold and alsoprevent the scaffold from changing its right angular parallelogram form.The scaffold cannot be folded or collapsed to the position o'f'Figurewithout removing the plank l-l firs't. -'Clips being resilient, they arecaa relatively the scaffold is arranged five-ply plywood of framemembers 23, at the pable of receiving the pipes 23 or the pipes 2'1,which are the larger corner frame members. Thus when the scaffold iscollapsed to the position of Figure 5, the clips 30 may be engaged onthe outside of two of the corner frame members 21, so that the platformis assembled with the frame also in the collapsed position.

Each leg I2 is provided at its upper end with a cap or cover 31,preferably of the type shown in Figure 6, wherein a tubular part fits inthe leg l4, and a projecting annular flange 38 overlaps the end of eachleg. The caps may be secured in place by friction or by through rivetsor spot-Welding; and the flange 38 must be small enough in diameter topass readily through the corner tubes 24.

When in the operative position the plank H, prevents the scaffold fromfolding because the clips 30 hold the frame members 23 parallel to eachother.

Referring to Figure 4, this shows the folded scaffold. In addition tothe assembly of the frame work and plank, as shown in Figure 5, Figure tshows the legs l4 arranged longitudinally of the bottom of the plank ll,the legs being alternately reversed in position so as to provide roomfor the casters.

The bottom of the plank II is, therefore, provided with a plurality ofthe same clips 30, so arranged that each leg is engaged by two of theclips 36 adjacent its ends, and thus the legs may be assembled and heldon the bottom of the plank when the scaffold is folded.

The operation of my folding scaffold is as follows:

Assuming that parts are folded, as shown in Figures 4 and 5, the legsshould first be removed from the bottom of the platform ll by merelypulling them out of their clips 30. Then the scaffold frames, comprisingthe four frames Iii-l3 and l2l2 are moved relative to each other,rotation taking place at each-corner until the collapsed frame of Figure5 is rectangular in plan.

The plank may then be placed on top of the horizontal end frame members23, and the plank may be secured to these horizontal end frame members23 by pushing the clips 38 over the. pipes 23.

One way of assembling the legs with the expanded frame is to turn theframe upside down at this time and to insert the four legs in the fourvertically open tubes that are provided by the corner frame members 24of the end frames 12.

The eye bolts 19 should be inserted through suitable apertures l8 in thelegs M to adjust the height of the scaffold. For example, this adjustment may'be such that the user can reach the ceiling with his hands, andhis head is below the ceiling. Of course the adjustment must'bedifferent for men of different size, but the present scaffold can beadjusted to any desired height and all four corners must have their eyebolts 19 located at the same height.

Assuming that the scaifold is now upside down, it should then beinverted so that the plank H is on top. The scaffold may then be movedto the desired place where it takes the place of two step ladders andthe usual extensible plank. The scaffold should then be secured in theposition to which it has been rolled by actuating two of the brakelevers IT on the casters l5.

All of the tubular parts of the presentscaffold are preferably madeoutof steel-so-as to secure a maximum strength with a minimum amount ofmetal.

In some embodiments of the invention aluminum alloys may be employed,provided they have the adequate strength.

It will thus be observed that I have invented an improved foldablescaffold for household use,

in which the platform may be located at any of a plurality of verticaladjustments to suit the user.

When the scaffold is extended, its plank holds it in this position. Whenthe scaifold is folded its plank must be removed from the top but it maybe secured to the side of the scaffold.

The legs are also slidably mounted in the tubular frame members 24, sothat the legs may be removed; and the legs may be secured to the bottomof the plank by means of spring clips.

The present scafiold is sturdy, capable of being locked in place,incapable of folding except by the intention of the user, and whenfolded it may be stored in a minimum amount of space.

The corner construction of the present scaffold is a matter of theutmost importance as it provides a maximum rigidity with the use of aminimum amount of metal.

While I have illustrated a preferred embodiment of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but desire to avail myself of all changes withinthe scope of the appended claim.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States, is:

In a folding scaffold for household use, comprising two identical sideframes, each having a first pair of short vertical corner tubes joinedby long horizontal tubes, two identical end frames, each having a secondpair of vertical corner tubes, long enough to project at each end fromthe first vertical corner tubes in which the second vertical cornertubes are rotatably mounted and confined by being welded at each end toa second pair of longer horizontal tubes, forming a foldableparallelogram frame, four elongated vertical leg tubes, each leg tubebeing slidably mounted in one of the said second vertical corner tubesand each leg tube having a multiplicity of transverse apertures, atransverse pin in one of the apertures of each leg tube, said pins beingengaged by the lower ends of said second corner tubes, and an elongatedplank overlapping the end frames when the parallelogram frame isrectangular in plan, said plank having a pair of downwardly extendingtwo-legged spring clips at each end, said slips being formed withpartially cylindrical portions receiving the horizontal tubes of the endframes, to hold the scaffold in open rectangular position and to retainthe plank on said horizontal tubes, said clips also being of sufficientsize to clamp two of said corner tubes to secure the plank and framestogether in folded position.

GEORGE G. THOMAS.

REFERENCES CITED The following references are of record in the SachsFeb. 22, 1949

